Comprehensive Review Maps Nicotine's Direct Cardiovascular Damage Across All Product Types

A comprehensive review published in Nature Reviews Cardiology has mapped the precise biological mechanisms by which nicotine damages the heart and blood vessels—and the findings apply equally to cigarettes, e-cigarettes, heated tobacco products, and oral nicotine, regardless of how the substance enters the body.

The research settles a question that has divided the field for years: whether nicotine itself is toxic to the cardiovascular system, or whether the damage comes primarily from smoking. The answer, according to the international team of cardiologists who conducted the review, is unambiguous. Nicotine is the culprit. When it binds to receptors on blood vessel walls, it triggers a cascade of cellular events that constricts vessels, promotes clot formation, and initiates a self-perpetuating cycle of inflammation. This happens regardless of whether the nicotine arrives via cigarette smoke, vapor, or a pouch placed between the cheek and gum.

The mechanism works through two separate but converging pathways. In the delicate inner lining of blood vessels, nicotine suppresses prostacyclin, a natural substance that keeps vessels relaxed and open. Simultaneously, it triggers the release of endothelin-1, one of the body's most potent vessel-constricting hormones. But nicotine does not stop there. It also acts directly on the smooth muscle cells that wrap around blood vessels, blocking potassium channels and disrupting calcium handling in ways that favor constriction. As one of the lead authors explained, nicotine disables the vessel's protective lining and then directly tightens the muscle surrounding it—two independent attack routes converging on the same catastrophic outcome.

The stakes are substantial. In 2023 alone, tobacco use killed an estimated 5.81 million people globally, with a further 1.66 million deaths among non-smokers exposed to secondhand smoke. Nearly 40 percent of these deaths were attributable to cardiovascular disease. More than 1 billion people worldwide currently smoke tobacco. The review establishes a clear hierarchy of harm across product categories: combustible cigarettes and waterpipes pose the highest risk, followed by heated tobacco products, then e-cigarettes, then oral nicotine products like chewing tobacco and pouches. Abstinence remains the only risk-free option.

This ranking directly contradicts the marketing claims that have surrounded e-cigarettes and heat-not-burn devices since their introduction. These products were promoted as reduced-risk alternatives to traditional cigarettes. The evidence presented in the review suggests they do reduce harm compared to combustion—but they do not eliminate it. They sit on a continuum of cardiovascular risk, not outside it. Removing combustion clearly reduces the damage, but nicotine itself continues to attack the cardiovascular system through the same biological pathways, regardless of delivery method.

The authors emphasize that nicotine is often marketed as a mild stimulant, something akin to caffeine. This characterization is misleading. Nicotine's dependence-forming potential ranks alongside cocaine and heroin. Combined with its direct cardiovascular toxicity at the molecular level, this creates a public health challenge that current regulatory frameworks are not equipped to address. Most countries regulate nicotine products individually—cigarettes under one set of rules, e-cigarettes under another, oral products under yet another. The review calls for a unified, nicotine-based regulatory approach that treats all nicotine-containing products as part of a single category.

The authors and supporting organizations, including the European Society of Cardiology, are calling for updated tobacco and nicotine regulation as part of broader cardiovascular protection efforts. They recommend greater efforts to prevent young people from initiating nicotine use in the first place, given the risk of addiction and the potential for lifelong exposure. They also highlight the importance of taxation, flavor bans, and evidence-based cessation support in addressing what they describe as an evolving epidemic of nicotine-product consumption. The question now is whether regulators and policymakers will act on the evidence.